Place the hazelnuts in a small-sized skillet. Lightly toast over low heat. Remove from heat and let cool completely. when the hazelnuts have cooled roll them around in a paper town to remove most of the skins. Chop them and set aside.

Mix the rutabaga, onions, flour, hazelnuts, and cheese in a large bowl.

Add the beaten egg and mix to combine thoroughly.

Season with salt and black pepper.

Heat the oil in the skillet.

Place a layer of paper towels beside the stove.

Shape the mixture into pancake-sized portions. They should be twice the thickness of pancakes but similar in diameter.

Flatten out each portion like a pancake. Add to the skillet and fry on both sides until golden.

Season the sour cream with kosher salt and freshly ground black pepper.

Serve the rösti with the seasoned sour cream.